Field of the Invention
The present invention relates to a secure data storage device, and more particularly to a secure data storage device that allows reading and writing operations and the methods thereof.
Description of the Related Art
Non-volatile memory or non-volatile storage is a computer memory which retains stored information even when it is not powered. Examples of non-volatile memory include read-only memory, flash memory, ferroelectric RAM (F-RAM), and different types of magnetic computer storage devices such as hard disks, floppy disks, magnetic tape, and optical discs. Non-volatile memory is typically used for long-term persistent storage.
Flash memory devices are electronic non-volatile computer storage media that allow accessing or reading stored data, writing new data and erasing stored data. In recent years, due to the overwhelming advantage of large memory size and high rewriting speed, flash memory has played a major role in the non-volatile memory market. Flash memories are used in a variety of applications, for example in USB drives for personal information storage, or embedded in credit cards or gift cards to enable financial payments or transactions.
Flash memory technology allows writing the value ‘0’ (zero) to any physical bit address in the storage device, and setting the values to ‘1’ (one) when erasing a block which includes a plurality of bits. The stored data remains intact between instances of device usage. However, tampering with the data stored in the device may be relatively simple, for example by illuminating the storage portion of the device with ultra-violet illumination or x-rays. For some applications, such as financial transactions, it is of significant importance to provide secure storage devices that cannot be easily tampered with. Such tampering may alter the stored data to facilitate fraud, e.g. a pre-paid gift card which has been tampered with may show a remaining positive amount of money (on the flash storage device), while the actual balance is zero.
It is desirable to provide a secure storage device, for example flash-memory based, which allows efficient storing and rewriting of data on the secure device, while improving the security and integrity of the data, and prevents tampering with the data stored in the device.